Author Topic: Carb spacer on a 427 side oiler?  (Read 850 times)

Carb spacer on a 427 side oiler?
« on: August 03, 2022, 11:51:08 PM »
My 69 GT500 has a (1968) 427 side oiler and it's been there for a very long time (Since the 70s).
It runs great and it runs a little on the hot side, but nothing to be too worried about, probably normal for this big block engine and the fact that I live in TX !
Once the engine is warm, it runs great at highway speeds but as soon as I slow to a stop or slow idle with engine hot (stop sign / yield sign / slow turn), the engine wants to die unless I keep my foot on the pedal and keep delivering fresh gas.  Ninety percent of the time, it dies right there on the spot, but it "usually" starts right back up.....then dies again until I keep giving it fresh gas.

When engine is cool it idles perfect.

I might be able to experiment with the timing a little to get it running a little cooler, but my guess is that the gas might be evaporating / boiling out of the bowls, which is why it starts back up again with fresh cool gas.

My car is a survivor and still has the factory original carb (rebuilt a while back) and the spacer that's with it "appears" to only be approx 1/2"

I was thinking that a 1" spacer might help the issue, but I wanted to check with those on here who might know what I'm up against.
If I change my spacer, I will have to adjust for the fresh air hood seal which I don't want to do (mine is original), unless I buy another one to experiment with.

Should I go another direction ?

Any suggestions ?


Thanks
Mike

Side-Oilers

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Re: Carb spacer on a 427 side oiler?
« Reply #1 on: August 04, 2022, 12:32:28 AM »
Sounds like fuel percolation.  First things I'd be trying:

Phenolic spacer. (Taller the better, but even a slight height improvement should help.

Electric fuel pump at the tank.

Wrap fuel lines in engine compartment.

This is a problem that probably 95% of us have encountered with our vintage muscle cars.  Keep picking away at protecting from high heat sources. Others here will have more good ideas.   
« Last Edit: August 04, 2022, 12:35:40 AM by Side-Oilers »
Current:
2006 FGT. Tungsten. Whipple, HRE 20s, Ohlin coil-overs, 3.90 gears. 210.7 mph.

Kirkham Cobra. 482-inch aluminum side-oiler. Tremec 5-spd.

Formerly:
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1970 Ranchero GT 429
1969 LTD Country Squire 429
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Bob Gaines

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Re: Carb spacer on a 427 side oiler?
« Reply #2 on: August 04, 2022, 02:13:13 PM »
To add . I insulated the clips at the bracket holding the 427 fuel filter can .  The bracket is heat by the engine block which in turn heats the fuel line.I also cut the tabs off holding the fuel log to the hot intake further isolating heat from the fuel line. It looks the same even though there are no tabs .The fuel log is easily supported by the steel fuel line and the lines going to the carbs.
Bob Gaines,Shelby Enthusiast, Shelby Collector , Shelby Concours judge SAAC,MCA,Mid America Shelby

shelbydoug

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Re: Carb spacer on a 427 side oiler?
« Reply #3 on: August 04, 2022, 03:18:55 PM »
There is a phenolic spacer/gasket available for the mechanical fuel pump. The 427 filter canister adds to the issue.

For me cutting the fuel tabs wasn't enough. I use a Delrin fuel log. never gets hot or cold.

I also went to a 00 cable from the starter to the solinoid. That cable previously would actually smoke when cranking.

The original size + cable is too small of a gauge for a BB and too small for my 347 as well.

It isn't all original but it starts hot. The BB fan and the C7ZX clutch are fine. No issues with those.

1/2" phenolic spacers under the carbs. Anything thinner was just not enough.

The two issues I had to solve were fuel peculating and not enough electrical power hot.
68 GT350 Lives Matter!

Bob Gaines

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Re: Carb spacer on a 427 side oiler?
« Reply #4 on: August 04, 2022, 04:07:49 PM »
There is a phenolic spacer/gasket available for the mechanical fuel pump. The 427 filter canister adds to the issue.

For me cutting the fuel tabs wasn't enough. I use a Delrin fuel log. never gets hot or cold.

I also went to a 00 cable from the starter to the solinoid. That cable previously would actually smoke when cranking.

The original size + cable is too small of a gauge for a BB and too small for my 347 as well.

It isn't all original but it starts hot.
The BB fan and the C7ZX clutch are fine. No issues with those.

1/2" phenolic spacers under the carbs. Anything thinner was just not enough.

The two issues I had to solve were fuel peculating and not enough electrical power hot.
  I also went to a 00 cable from the starter to the solinoid. That cable previously would actually smoke when cranking.

The original size + cable is too small of a gauge for a BB and too small for my 347 as well.

It isn't all original but it starts hot.
Or you could get a gear reduction starter like all the online speed shops sell and not have to make up special heavy cable because the original wiring works fine. It will look original from up top where everyone looks. It will start hot .
Bob Gaines,Shelby Enthusiast, Shelby Collector , Shelby Concours judge SAAC,MCA,Mid America Shelby

Royce Peterson

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Re: Carb spacer on a 427 side oiler?
« Reply #5 on: August 04, 2022, 06:13:03 PM »
The original '68 side oiler has a hard rubber spacer between the carb and the intake that is about 3/8" thick. Bill at Mansfield Mustang has the piece in stock. The same part was also used on the '68 428CJ and GT500KR.

There''s not a vapor lock issue with these engines ever if the fuel system is completely stock with the 4441S pump, etc. A cracked spacer between the car and intake is a problem. Cracked intakes are not unheard of either.
1968 Cougar XR-7 GT-E 427 Side Oiler C6 3.50 Detroit Locker
1968 1/2 Cougar XR-7 428CJ Ram Air C6 3.91 Traction Lock

Re: Carb spacer on a 427 side oiler?
« Reply #6 on: August 04, 2022, 10:14:17 PM »
Lots of good suggestions here, many thanks to all !
I will review, make a list, and start crack-a-lackin...